728638 has 8 divisors (see below), whose sum is σ = 1101240. Its totient is φ = 361560.

The previous prime is 728627. The next prime is 728639. The reversal of 728638 is 836827.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1033 + ... + 1588.

It is an arithmetic number, because the mean of its divisors is an integer number (137655).

2⁷²⁸⁶³⁸ is an apocalyptic number.

728638 is a deficient number, since it is larger than the sum of its proper divisors (372602).

728638 is a wasteful number, since it uses less digits than its factorization.

728638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2762.

The product of its digits is 16128, while the sum is 34.

The square root of 728638 is about 853.6029521973. The cubic root of 728638 is about 89.9851004142.

It can be divided in two parts, 728 and 638, that multiplied together give a palindrome (464464).

The spelling of 728638 in words is "seven hundred twenty-eight thousand, six hundred thirty-eight".